Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 301739
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
139 PM EDT TUE AUG 30 2016

.UPDATE...
Issued at 1054 AM EDT Tue Aug 30 2016

Pretty quiet thus far this morning with just an isolated shower
or two to contend with across the forecast area. Going to be
interesting just how much convection we can pop off this
afternoon with a decent amount of instability (1000-1500 j/kg of
mixed layer capes) out ahead of the approaching surface cold
front. Do not think the coverage will be more than scattered so
have left in the chance wording. Chances of severe appear to be
limited with only 25 to maybe 30 knots of bulk shear to work with
but you never know given the instability/front.

&&

.SHORT TERM...(Today and tonight)
Issued at 347 AM EDT Tue Aug 30 2016

High impact weather potential: Scattered thunderstorms. Severe
weather not expected.

Pattern synopsis and forecast:

High pressure was over the eastern Great Lakes and much of western
Canada early this morning. In between, an area of low pressure and
it`s associated shortwave trough were in nrn Ontario. A cold front
extended south of the low, through western Lake Superior and srn MN.
A band of showers with embedded thunderstorms was laid out along and
ahead of this front, buried within a theta-e/instability max, and
forced/sustained by weak shortwave energy/vorticity in fairly weak
flow aloft and right entrance region jet dynamics. Nrn Michigan was
only seeing some convective debris clouds, primarily across eastern
upper, however there have been some new showers/storms trying to get
going around Whitefish Bay.

The cold front will cross eastern upper by early afternoon, then
sweep across nrn lower by late this evening. The air mass will be
fairly rich with low level moisture, and this air mass combined with
decent daytime heating and an analyzed vorticity maximum set for
late morning to afternoon, ought to make it pretty easy to develop
at least scattered showers and storms along and ahead of the cold
front. Fairly unimpressive lapse rates of 6c/km ought to negate some
of the expected 1000-1500 MLCAPE to keep updrafts from producing any
widespread severe weather, especially with relatively weakish flow
aloft. Should be more garden-variety type thunderstorms, but
isolated severe storms are possible. Chances for rain wane heading
through the overnight hours.

High temperatures today will range from the upper half of the 70s in
eastern upper to the middle 80s closer to Saginaw Bay. Lows tonight
in cool advection will generally be in the middle to upper 50s.

.LONG TERM...(Wednesday through Monday)
Issued at 347 AM EDT Tue Aug 30 2016

Models are in good agreement with surface high pressure beginning to
build into the region Wednesday...however an upper level trough and
some lingering moisture will be enough to keep partly to mostly
cloudy skies around through Wednesday night. The surface high
pressure continues to build as long as rebounding
heights...diminishing any remaining clouds Thursday. Light winds and
clearing skies may allow enough radiational cooling for some patchy
fog to develop over interior portions of northern Michigan Thursday
morning...but will be a better chance Friday morning as the surface
high centers over the Great Lakes region. This negative PNA setup
continues through the weekend with daytime temperatures only in the
upper 60s to low 70s through Friday and finally beginning to
moderate during the weekend...reaching into the upper 70s and low
80s as said surface high pressure begins to finally move to the east
of the CWA. Lows will be in the upper 40s to mid 50s through Sunday
morning and then only drop to the low 60s as the warmer
southwesterly flow develops. Return moisture arrives late Sunday
into early Monday ahead of a low pressure system near Hudson Bay,
returning chances of showers/thunder through the remainder of the
period as the forecast area sits under the eastern periphery of a
broad upper level trough, possibly the sign of a more cloudy and wet
change in the pattern to remain for several days to come thereafter.
The National Hurricane Center is also keeping an eye out on several
tropical disturbances. Depending on the exact strength and track of
any tropical system that develops, it could obviously change the
ongoing forecast.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 136 PM EDT Tue Aug 30 2016

A surface cold front will move across the taf sites this afternoon
and evening. There will be isolated to scattered showers with an
embedded thunderstorm or two through that time. Winds will shift
into the north and northwest behind the front and be a little
gusty on Wednesday. Cigs are expected to be largely vfr but could
sneak into the mvfr category from time to time.

&&

.MARINE...
Issued at 347 AM EDT Tue Aug 30 2016

High pressure was over the eastern Great Lakes and much of western
Canada early this morning. In between, an area of low pressure was
in nrn Ontario, with a cold front extended to the south through
western Lake Superior and srn MN. This front will cross the Great
Lakes today and tonight bringing scattered showers and storms. SW
winds will veer westerly, then NW tonight behind the departing
front, with low end advisory level winds briefly possible. There is
a better chance for advisory level winds late Wednesday and
Wednesday night as the Western Canada high pressure shoves into the
central and nrn plains.


&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...Sullivan
SHORT TERM...Dickson
LONG TERM...TJL
AVIATION...Sullivan
MARINE...Dickson



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